This application requests five years of support for the Center of Demography and Ecology, University of Wisconsin-Madison. CDE is a high-profile research center in population with affiliates in 11 departments and 4 colleges. It has held NICHD Center Grant funding since 1972;this application requests continuation of that support under NICHD's Population Research Infrastructure Program (R24). Support is requested for four research support cores - Administration, Computing, Information Services and Methodology- and for Developmental Infrastructure. The Population Center Grant would support a collection of scholars whose research spans the field of population studies. During the past five years, CDE has aggressively recruited top young scientists, strengthened ties and developed new forms of cooperation with departments, research centers and institutes in fields cognate to population studies. Our research portfolio has become more diverse, is more international in character, and covers a greater portion of the life course than in the past. CDE researchers work in a broad spectrum of topics, but four clusters constitute our signature themes: (1) Health and Mortality;(2) the Demography of Inequality;(3) Fertility, Families, and Households;and (4) Data and Methodology. In addition to innovative research in each of these areas;CDE researchers continue to collect and produce high-quality data for the use by the population research community. Continued investment in CDE will leverage substantial commitments from the University, a large portfolio of individual research grants, and outstanding human and organizational resources to promote interdisciplinary research on population issues. RELEVANCE: Changes in childbearing, the gradual increase in life expectancy and the global mobility of people create an unending stream of questions that population research may address. Demographic behavior and outcomes affect social organization, health services and economic growth. CDE will help to address these challenges as an innovative and flexible provider of research collaboration, training, and infrastructure.